Link mechanism for circuit breakers



Nov. 27, 1928.

D. RGNNBERG ET AL LINK MECHANISM FOR CIRCUIT BREAKERS Filed June 1926INVENTORS DAMEL R5NNBERG ADOLF RooTH ATTORNEY Patented Nov. 27, 1928.

UNITED STATES DANIEL nonnnanalmn. mom: BOOTH,

or LUDVIKA, swnnnn, assrenoas To ALL:

HANNA SVENSKA,ELEKTBIBKA AK'IIEBOLAGET, OF VASTERAS, SWEDEN, A COB-PORATION OF SWEDEN.

mm: non cincurrnnnaxnns.

Application filed June 4, 1920,

In circuit-breakers, which are' enclosed in a tank containmg a coolingmedium, for in stance oil, and whichare operated by means.v

of a shaft projecting through the wall of the tank, it is of a certainimportance to enable the movable contact members to be moved through alarge distance by'a comparatively small rotation of Tthe shaft. Thepresent invention hasfor its object to provide a l nk mechanism forcircuit-breakerspermitting such an operation. v

A form of the invention is illustrated in the accompanying drawing,where Fig. 1 shows a circuit-breaker with the link mech anism in afrontview tion, while Fig. 2 shows a simplified geometrical view of thelink system in three difierent positions. I 1 7 .In the tank laretwostationary contacts 2, 2' adapted to be connected by a verticallymovable bridge contact 3. The latter is guided by one or more rods %1and is operated ymeans of acrank and pitman mechanlsm, consistin ofalink 5 and :3 on a sha t 7. ,Whenthebreaker is moved from closed to openposition ,or vice verse2 this shaft should be rotated about-one hal turnfor eifectin the largest 'possible-niovement of the bri ge piece 3.

The breaker is operated by means of a shaft 8 projectingthrough t e'wallof the tank. For certain reasons, for instance, in order to provide asimple operation of several poles of the breaker by means of adrawbar,.it may be desirable to rotate the said shaft 8 only a quarterof aturn' for efiectmg the closing. or breaking operation. Fortransmitting the motion from shaft 8 to shaft 7 and simultaneouslydoubling the 40 angle of rotation, there is used one arm 10 mounted onthe former and one .arm 9 mounted on the.latter and alink 11 connectingboth arms. The arm 10 "should be considerably longer than-for instanceabout twice as long asthe arm 9, andthe' length of the link 11 shouldlie between those 0 the two arms. Theaspect of the link system in threedifierent positions is di atically shown in Fig. 2, viz in full-drawnlines 0 in one extreme position (corresponding to and the tank, in secanarm 6 fixed.

shaft actuates the movable contact.

Serial No. 118,689, and in Sweden June 19, 1925.

closed contacts), in dash-lines in an intermediary position and indotted lines in the other extreme position (corresponding to opencontacts) It is evident from Fig. 2, that the arm 9' is rotated one halfturn as the arm 10 is rotated a quarter of a turn.

For giving appropriate angles between the arms and linlr in differentositions the center of the shaft 8 should he approximately in theextension of the arm 9 when the latter occupiwits middle position butrather large deviations from this r e are possible without appreciablyinterfering with the o eration of the mechanism. The arms and ink may ofcourse be curved, as shown in Fig. 1, if this is found necessary forproviding space for other members of Y the mechanism.

We'claim as our invention:

1. In a circuit breaker having a fixed and a movable contact, anoperating shaft adapted to turn through approximately 90 an operatedshaft mounted adjacent and paral el to the operating shaft and adaptedto turn through approximately 180, an arm secured on the operatingshaft, a relativel short arm secured on the operated shai t a linkconnecting said arms for transmitting turning movement from theoperating to the operated shaft-the operating shaft being so disposedrelatively to the ath of move-v ment of the said short armtlxat'the-latter may be swung freely throu h 180 .by the said linkwithout bringin t e ends of the link and the operated sha' into lookingor dead-center positions--, and connecting means between the operatedshaft and the movable Contact whereby rotation-of the said 2. Acircuit-breaker enclosed in a tank containing a coolin medium, andcomprising an operating s aft projecting through the wall ofsaid tankand adapted to turn through approximately a second shaft mounted in thetank parallel to the first f shaft, an arm fixed on the latter shaft, a

link slightly longer than the arm and connected thereto, a second armabout twice the length of the first one connected to said link and fixedon the first-mentioned shaft which is situated approximately in theexposition-, and crank mechanism connecttension of said first arm-whenthe latter oc- 1ng said second shaft to a movable contact 10 oupies aposition half way between itstwo of the circuit-breaker.

extreme positions-so that the first-men- In testimony whereof we havesigned our 5 tioned arm may be swung freely through names to thisspecification.

approximately 180? by the said link without bringing the ends of thelink and the sid DANIEL RONNBERG.

Second shaft into a looking or dead-center ADOLF ROOTPL'

